The easiest, quickest and savest way for me to pry off the belt cover for the first time, was to take a long screwdriver or rod or thin pipe or some other long and thin tool (pry bar tool) and tap it against the lower prypoint through the rear wheel from the right side (the muffler´s side) with a hammer gently. Just so much that the gasket broke loose a bit. Then also pryed off a little bit at the upper prypoint. Once the gasket broke it was a homerun.
You probably might need a new gasket. I greased the new gasket with high temp grease lightly afterwards and never had any issues installing or removing the beltcase-cover at later inspections. It´s sort of a paper gasket only.... and Kymco glues it in there for the first time, I guess for warranty control reasons.
When reinstalling the belt, make sure that the belt sits loose between those variator driven pulleys so that you can torque the outer pulley to the correct torque specs onto the crankshaft. This is very important and must be done correctly. Otherwise you might end up with a total disaster if that pulley came loose afterwards.
What is the correct torque spec? Well, another mystery from Kymco here. I researched, asked mechanics and got values ranging from 50NM up to 93NM. I found 50NM a bit on the low side and 93NM a bit on the high side and so I took the average 70NM (dry - not oiled - no Loctite) and so far it has kept all together for at least two times now.
Belts do also have a rotation direction. Be aware of that, while you intall it. You should be able to read the letters and numbers on the belt normally from left to right and not upside down while standing in front to that open beltcase.
There is also lots of good but also some wrong and bad info material out there in the internet.
Good luck!